1. Field of the Invention
The present invention relates generally to a delivery apparatus for folding machines for forming signatures by selectively changing over a straight run for cutting a paper web into cut-length sheets of a predetermined length and sequentially folding the cut-length sheets in a folding apparatus, and a collect run for overlapping two sheets of the cut-length sheets in the folding apparatus and subsequently folding the two overlapped sheets, then placing the formed signatures onto an in-service conveyor via a delivery fly to deliver the signatures in a state where the forward face of the signatures is caused to feather, or to be offset overlapped, and more particularly to a folding machine for allowing signatures to be discharged by making the feathered overlap pitch of the signatures in the straight run the same as the feathered overlap pitch of the signatures in the collect run where the number of signatures to be formed is half, for example, as many as the number of signatures to be formed in the straight run.
2. Description of the Related Art
A conventional type of delivery apparatus for folding machines having the aforementioned construction as disclosed in Japanese Published Unexamined Patent Application No. 2000-185858 is publicly known. The prior-art delivery apparatus for folding machines disclosed in that Patent Application has a variable gear-ratio gear drive provided between a drive gear operating in conjunction with a folding apparatus and a drive shaft of a discharge conveyor, in which the gear ratio of the gear drive is changed in accordance with the changeover from a straight run mode to a collect run mode so as to change only the operating speed of the conveyor with respect to the operating speed of the folding apparatus, that is, so as to make only the operating speed of the conveyor slower with respect to the operating speed of the folding apparatus when changing over to the collect run, so that signatures can be delivered with the feathered overlap pitch of the signatures in the straight run made equal to the feathered overlap pitch of the signatures in the collect run.
Heretofore, signatures formed in the folding apparatus are placed on the conveyor via the delivery fly in such a manner that a succeeding signature is placed on the conveyor after moved at the operating speed of the delivery fly to a position where the succeeding signature overlaps a preceding signature that has been placed on the conveyor offset by a predetermined distance. Consequently, the portion of the succeeding signature that runs off the receiving area of the delivery fly tends to be unwantedly moved while coming in contact with the preceding signature that has been previously placed on the conveyor earlier.
In the prior art disclosed in Japanese Published Unexamined Patent Application No. 2000-185858, the feathered overlap pitch of the signatures in the collect run is made equal to the feathered overlap pitch of the signatures in the straight run by making the operating speed of the conveyor slower while the operating speed of the delivery fly for transferring the signatures received from the folding apparatus to an appropriate position on the conveyor is kept matched with the operating speed of the folding apparatus. This construction could cause the following problem. That is, as the succeeding signature that has been moving at the operating speed of the delivery fly are placed on the conveyor in an uncontrolled state and is now moved while coming in contact with the preceding signature that is moving at the operating speed of the conveyor, the preceding signature is forced to move together with the succeeding signature, causing a large deviation in the feathered overlap pitch. This may result in troubles in handling the signatures with handling means on the downstream side, such as failure to grip the signatures one by one with the grip transfer device.